Binder composition for abrasives and other materials and method of making same



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COATING R PLASTIC.

Patented Sept. 8, 1925.

Uross Reference 1,553,105 PATENT OFFICE.

HENRY 3. POWER, NIAGARA FALLS, NEW YORK, ASSIGNON TO THE CARBORUNDUM COIPANY OF NIAGARA FALLS, NEW YORK, A CORPORATION OF PENNSYLVANIA.

BINDER COMPOSITION FOR ABRASIVES AND OTHER MATERIALS AND METHOD OF MAKING SAME.

No Drawing.

at ork,

have invented a new and useful Improvement in Binder Compositions for Abrasives and Other Materials and Methods of Making Same, of which the following is a full, clear, and exact descriptioii.

10, I will first describe the process as applied to abrasive compositions, although, as will hereinafter appear, the invention is not .limited to such compositions.

' Abrasive compositions have been made in the past by bindin the abrasive material and a filler with or inary Portland cement, with or without a igment. Such compositions may be made y either a dry or a wet process. The dry process consists in H1015- tening the mixture of abrasive grain, filler and Portland cement sufiiciently to enable the article to be pressed into shape. The molded article is then dipped in water to cause the final hydration or setting of the a neeu a'alea December 11, 1919. semi ire. 44,181.

moistened'with a suflicient quantity oi water to permit of molding. The mois ne -mix is placed in a mold and -ressed into the desired shape, using a hyiafil'mress or similar device.

The molded article is then ready for its initial setting, which is accomplished by placing in waterfor a short time. The arhole or abrasive composition thus initially set must then be given its final treatment, which is the novel part of my invention. The article is laced in an atmos here of carbon dioxide e1 er a norma or inms, and allowed to remain several hours. I prefer to treat the article in a closed receptacle at a pressure of thirty pounds per square inch. After this treatment, thearticle again is placed in water for a short time, again removed and again treated with the gas. This process is repeated until the proper density is secured, which requires several days. The process may, however, be carried outin the wet way as'follplvs: A mortar is madeof abrasive cement. The wet or'pudd'ling process con-kirai hydrated limera fillegiortland ce and water. H

sists in mixing the abrasive grain, filler and Portland cement withv sufiicient water to, give a 'mortar which is'poured into the mold while in wet condition. In both proc- 30 esses, the articles are allowed to set 0 harden in ordinary or damp air.

The objections to these methods are the nonhomogeneous structure of the finished article, and the deficiency in the hardness,

35 strength, density and other desirable physical properties. To overcome these ObjGC'.

. tions, therefore, I have invented a new mixture and also a new process for treating it, which mixture and rocess is as follows.

TQ dry zortlan cement are added an abrasiv gram, suc as garnet, sand cstalline alumina, eme s1 icon car 1 e e e'iflier singly o r as"'a' mi ure of the difi erent grains,.together with the proper pigment in 45 the form of a dry color and a certain amount of d h drated lime chemic'ally known as (lall ll 'Tlie amount of hydrated lime which I use varies according to the prodnet to be made by the process. In general,

50 the amount of hydrated lime used runs from 10% to 30% of the amount of Portland cement introduced into the mix. The dry materials, after a thorough mixing in the usual machines appliedto this'purpose, are then an t is fnortar is poured so into a mold and allowed to undergo 1ts ini tial set. When .stron enough to remove from the'mold, the article is treated or artificially aged by carbon dioxide gas, substantially as described above in the dryprocess.

The carbon dioxide reacts with the calcium hydrate, forming carbonate of lime, or artificial marble, the hardness and structure of whichv is quite different from that which results when cement alone is used. The water freed from this reaction, viz:

serves to set the cement in situ, giving a homogeneous structure of artificial marble and cement. This is shown on the fracture of the finished stone, which is smooth or ponchoidal, rather than sharp and 'hackly. The superiority of such an article is shown in its water-resisting qualities. A Portland cement composition made by the ordinary process of setting cement will absorb water when immersed in it. The composition made by the process herein described -will show no absorption whatever, or atmost very little, absorption, during the same length of time of immersion. This is an advantage because particles of steel or other umalllllltd an V material freed by the abrading process when the articles are in use do not fill up the pores of the stone, and may be washed oil from the surface.

Among the abrasive articles which may be advantageously made by the process herein described are sharpening stones, grinding wheels and also other abrasive devices in which great density, hardness, strength, homogeneity and waterproofing qualities are desired. a

I do not limit my invention to the making of Portand cement compositions which are used for abrasive purposes and in which the aggregate consists only of abrasive particles. My invention has a wide application in Portland cement compositions of various descriptions, in which the aggregates may consist of sand, crushed stone, gravel, or any of the ordinary materials commonly used for aggregate. Among these applications are concrete receptacles for holding liquids, structural concrete forms, concrete floors, tile, etc. The term aggregate, as used in my claims, refers to the material which is bound together by the cement or other binder, whether such a material is an abrasive in character or otherwise.

I claim:

1. The method of making a cement composition, which comprises forming a cement mixture containing calcium hydrate and subjecting the mixture to the action of carbonic acid gas to thereby convert the calcium hydrate. into a calcium carbonate.

2. The method of making a cement composition, which comprises forming a cement mixture containing calcium hydrate, shaping an article therefrom, and subjecting the article to the action of carbonic gas to thereby converta portion of the calcium hydrate into calcium carbonate.

3. The method of making a Portland cement composition, which comprises shaping an article from a mixture containing aggregate, Portland cement and calcium hydrate, and subjecting the article to the action of carbonic acid gas to thereby convert the calcium hydrate into calcium carbonate.

at. The method of making a Portland cement composition, which comprises forming a mixture of aggregate, Portland cement and calcium hydrate, molding the same into the desired form, and subjecting the molded article to the action of carbonic acid gas under pressure to thereby convert the calcium hydrate into calcium carbonate.

5. The method of making a Portland cement composition which comprises forming a mixture of Portland cement, calcium hydrate and abrasive particles, molding the same into the desired form and subjecting the molded article to the action of carbonic acid gas to thereby convert calcium hydrate into calcium carbonate.

6. The method of making a Portland cement composition which consists in forming a cement mixture containing hydrate of lime and abasive particles, molding the same into the desired form and subjecting the molded article to the action of carbonic acid gas to thereby convert calcium hydrate into calcium carbonate.

7. A Portland cement composition comprising aggregate united by a combination of Portland cement binder and calcium carbonate formed in situ by the action of carbonic acid gas on calcium hydrate.

8. A Portland cement composition, comprising abrasive particles, Portland cement and hydrate of lime hardened by the irction of carbon dioxide on the hydrated ime.

9. A Portland cement composition, comprising abrasive articles, a Portland cement binder and ydrate of lime, some of the hydrate of lime being converted into carbonate of lime in situ by the action of carbon dioxide and the finished composition being characterized by having such a dense structure that it gives a conchoidal fracture.

10. The method of making articles of a composition, comprising forming a mix of dry Portland cement and abasive'particles, together with hydrated lime to about 10% to 30% of the cement, mixing the materials, moistening the mixture and shaping the articles from the moistened mixture, initially setting the shaped articles by the use of water, and then treating the initially Set articles in a closed receptacle to the action of carbon dioxide and thereby converting the calcium hydrate into calcium carbonate.

In testimony whereof, I have hereunto set my hand.

HENRY R. POWER. 

